Control apparatus



April 22 1924. 1,4%159 R. F. METCALFE CONTROL APPARATUS Filed March 5. 1923 2 Sheets-Sheet l.

April 22 1924.

R, F. METCALFE CONTROL APPARATUS Filed March 5. 1923 2 Sheets-Sheet 2 Patented Apr. 22, 1924.

UNITED STATES PATENT OFFICE.

ROBERT F. METCALFE, OFVERIE, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, T SOCONY BURNER. CORPORATION, 0F WILMINGTON, DELAWARE, A COR- PORATION OF DELAWARE.

courant, APPARATUS.

Application lef Merch 5, 1928. Seriallo. 62280.

To all whom z't may concern:

Be it known that l, ROBERT F. METCALFE, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented new and useful Improvements in Control Apparatus, of which the following is a specifica-tion.

The invention is designed particularly to control burners. llVith such burners it is usually desirable to have them running in response to certain outside conditions, as for example, room temperature, and to have them off as the room temperature changes.

With some kinds of burners, particularly those using liquid fuel it is desirable to provide some means of control which will close off the fuel supply when there is a failure of ignition with a setting of the control apparatus to affect the operation of the burner. Such devices have been attempted and l have illustrated and described one in my application tiledY Oct. 2nd, 1922, Serial No. 591.768. The present invention is designed to simplify such a control.

The invention is illustrated in the accompanying drawings as follows z- Fig. 1 shows a plan view of the controlling switch and motor.

Fig. 2 a front elevation of the same.

Fig, 3 a side elevation of the burner and operating parts.

Fig. 4 an end elevationof the burner.

Fig'. 5 a diagrainmatical view of the burner and the elements o'f control and the operating and controlling members.

1 marks the burner, 2 a fuel jet leading to the burner, 3 an ignition pocket and preliminary burner, 4 a. spark plug forming a means of ignition, 5 a fuel supply pipe lead- 40 ing from a source of supply 5a to the jet 2` 6 the air nozzle of the atomizing jet, 7 a pipe leading from the air nozzle to a pump 8, 9 a

piston operating in the pump, and 10 a pitnian leading from the piston and,having a strap 11 operating on an eccentric 12. The eccentric 12 is mounted on a shaft 13. A worm gear 14 is also mounted on the shaft 13 and is driven b v a worm 15. The worm 15 is mounted on a shaft 16 which is the rotor shaft. of a motor 16a.

A fan 17 is mounted on the shaft 16. This is arranged in the fan case 18 and connected by a pipe 19 with the air inlet passage-20 .leading to the burner, the passage 20 communicating by a passage 21 around the end of the ignition chamber' 3 and leading into the burner proper 1. It will be seen, therefore, that as the pump is put in operation supplying air under high pressure through the pipe 7 to the atoinizing jet the fan 17 is at the same timeY put in motion supplying the volume of air for combustion.

The line wires 22 and 23 extend to the burner motor, the line 23 being connected by a wire 24 with one of the brushes 26. A wire 27 leads from the wire 22 toa post 28. A switch plate 29 has the contact point 30. A contact point 31 operates in connection with the point as a switch and is mounted on a plate 32. The plate 3 2 is carried by a. post 33. The post 33 is connected by a wire 34 with a brush 35 of the motor 16a. When. therefore, the contact point 31 is moved into contact with the point 30 line current is delivered to the motor and the burner motor operates to continue the burner in ruiming condition so long as the room conditions, or other conditions remain so asto make the running condition desirable. l

rlhe plate 32 has a cam riding projection 36 which operates on a cam 37. The cam 37 is mounted on a controlling switch shaft 38. lt is provided with a notch 39 which lets the projection drop so as to break the connection through the contacts 31-30 and a riding surface 40 which holds these points in contact.

A contact point 41 is mounted on the plate 32, being insulated therefrom, and operates in connection with a point 42 to form a switch which is closed when the switch with the contacts 31-30 is closed. The point 41 is connected by.a wire 43 with a bridge plate 44 and this plate is connected by a wire 45 with a spark coil 46. A wire 47 leads from the coil 46 to the spark plug 4, being grounded in the usual manner at the spark plug and through a ground 48. A wire 49 leads from the coil to a breaker plate 50 which is actuated by a breaker cam 51 on the rotor shaft 16. The breaker plate 50 operates a switch in connection with the breaker post 52 which. is grounded at 53. Consequently when the burner motor is running the breaker is running. r1`he contact point 42 is carried by a spring plate 54 mounted on a post 55. A Wire 56 leads from the post55 to a Wire 57. The wire 57 leads from a transformer 58 which is energized by wires 59 and 60 leading from and tothe wires A Worm gear 61 is mounted on the shaft 38 and is driven by a worm 62. The worm 62 is mounted on a rotor shaft 63 of the control motor 64. A wire 65 extends from the transformer 58 to one post of the control motor and a Wire 66 leads from the opposite post to t-he ground. A fan 67 is arranged on the rotor shaft 63 to reduce the control speed of the mot-or to some extent.

In operating the device the control motor operates the controlling switch, the controlling switch asl it moves forward breaking the circuit through the control motor so that the burner switch 30-31 is maintained either in open or closed position at the different stops as the control motor circuit is opened. In t-he present invention the circuit operating the controlling motor is directly 'controlled by the cont-rolling switch without the intervention of relays or other locking devices and thisis made possible by the construction of thel switch..v Further it is possible with this construction to use but one circuit fromsome of the controlling elements as distinguished from the double lines of my prior application. l brush arm '68 is fixed on-the shaft 38 andA insulated andlgrounded by any convenient means, as by a wire 71." has the brushes 69 and 70. These brushesf'tiiaverse a series ot switch plates which may be designed as the norma-1 running or on plate 72, the emergency stop or ofi` plate 73. the starting or retarding plate 74. the emergency plate 75. and the cmergencygstop plate 76. The running plate 72 is ctnnected `with the extensions circumterentiallyfrom the emergency stop plate 76 having a radialposition coincident with the plate 75 and the brushes 69 and extend over these two plates simultancousl)v` when the arm reaches a posit-ion to bring the brushes in register with them.

ln the operation ot' this switch. starting with the brushes in the normal stop position. or ofi' position on the plate 73 as shown. when the thermostatic control reaches the cold side the current is connected through the control motor, and advances the brushes ott the plate 73 on to the plate 74. The plate 74 continues the connection through the control motor so that the control motor continues running until the brush is brought over the plates 72 and 75. lf the burner has started and is running normally the connecfion through the plate 75 will be breken and there will be no connection through the plate 72. The t-hermostatic control reaches the warm side. When this happens the brush moves forward off the plates 72 and 76 on to the plate 73 the stopped position. If, however, when the brush reaches a position over the plates 72-75 by reason of a lack of normal conditions in the burner a connection is established through the plate 75 and the motor is continued until the brush is brought 75 ofi the plate 75to the emergency stop position'76 where it is locked and remains until it may be manually started. This briefly gives an outline of the operation of the switch. The various circuits and elements for accomplishing this are as follows:-. The thermally responsive element 77 operates between the cold contact plate 78 and the hot contact plate 79 ordinarily referred to as the hot and cold side' of the thermostatic switch. A Wire 80 extends from the cold side to a bridge plate 8l and this 'l's connected by a wire 82 with the stop plate 73. A wire 83 extends from the element V77 to the wire 57. A wire 84 leads from the wire 57 to a bridge plate 85 and a wire 86 leads from the bridge plate 85 to the starting plate. 74. It will readily be seen. therefore. as the thermal element reaches the cold side 79 with the brushes in the position shown in Fig. 5 a. circuit is established by way ofV the ground. brushes` plate 73. wire 82, bridge 8l, wire 80. through the thermostat` wire 83. wire 57, 65. the. I motor` and ground 66, and this starts the controlling motor moving the brush ou to the starting plate 74. Here the circ-uit is continued by the wire 86 connecting with the wire 57. the circuit being otherwise the samel y The brushes 69 and 70 so operate on tht` plates as to establish a contact with the suc cecding plate before leaving the preceding plate. Thus a circuit is established through the plate 7 et before it is broken through the plate 73. no

The brush moves forward on to the plate 74 and at the same time the cam 37 advances moving the surface 40 under the projection 36 so as to close the switch 31-30 and start the burner motor. The same action ener-4 gizes the spark plug and prepares for ignition. The plate 74 is sufficiently long at the speed ot the motor to give the burner ample time for ignition and for assuming approximately normal, conditions before the brush reaches the plate. 72-75. As the brush passes ott' of the plate 74 on to the plates 72-75 if the conditions are normall the circuit through the control motor is opened and the control motor stops leaving the projection 36 on the surface 40 and the switch 30-31 closed. The burner motor. therefore. continues to operate until the thermal element 77 reaches the hot side78. The hotside 7.8 is connected by a wire 89 with the .l

emergency plate 76'from which the running plate 72 extends. The brush remains on the p-late 72 until the closing of the warm side of the switch 7 71-7 8 when a circuit is established by way of the brush and its ground and through the thermal element, wire 83, wire 57 to the control motor. The control motor, therefore, under these conditions is started and the brush is moved forward until the circuit is broken by the brush moving otf on to the stop plate 73.

When the brushes reach the point over the p-late 76 the projection 36 drops 0H the surface l0 and opens the motor switch. Thus the control motor will alternately advance the brush responsive to changes of temperature of the thermostat so long as normal conditions prevail. When, however, there is a failure of ignition either by lack of fuel or failure of the spark plug it becomes very essential that the burner be stopped and it is, therefore, desirable to prevent the stopping of the brushes 69--70 on the running plate 72. For this reason the emergency plate is provided which is covered by the brush simultaneously with the plate-72 and this forms a connection through a switch responsive toburner conditions. l prefer the switch here shown but in a general way any switch responsive to burner conditions may,i

be used. A passage extends from the burner chamber and is responsive to burner chamber pressures. This terminates in an insulated ring 91 in which is mounted the shutter or liapper 92. The dapper is hinged at 93 and free to swing outwardly when subjected to pressure from the burner chamber, the amount of resistance being regulate-d by a screw weight 94. The flapper when free from the burner pressure rests on a contact post 95. This post is connected by a wire 96 with the wire 57 which is, as before described, in circuit with the controlling motor. A wire 97 is connected with the flapper 92 by way of the hinge and extends to a bridge plate 98 which is connected by a wire 99 with the plate 75.

The operation of this safety switch is as followsz-lf there is ignition in the burner there is immediately created a pressure due to expanding gas which is delivered to the fiapper and this moves the dapper outwardly out of contact with the post 95, thus breaking the connection from the plate 75 to the wire 57. Consequently when the brush reaches the plate 75, the circuit through the plate 72 being opened, there is no circuit leading to the control motor and the control motor stops and the brush remains on the running plate with the switch 30-31 closed so that the burner may continue running until altered by the thermal conditions operating on the thermostatic element 77. lf. however, there is a failure of ignition and a consequent failure of pressure in the burner chamber, the flapper 92 remains in contact with the post and a circuit is established bet-Ween the plate 75 and the wire 57 and consequently through the control motor. As a result the control motor does not stop when the brush passes from the plate 74 to the plates 72-75 but continues until the brush passes ofi' the plate 75 on tothe plate 76. This is termed the emergency stop position and the motor being out of circuit when the brush ,reaches this position it stops. ln this position the projection. 36 is dropped ofi` the surface 40 and the switch 30-31 is opened so that the burner motor is stopped and at the same time, as a matter of economy, the ignition circuit is opened by opening the switch `When the veonditions of the burner are satisfied it is desirable 'to be able to start the device conveniently and this can be done by closing the connection through 1the emergency stop plate 76. A push button switch 100 is operated by a push button 101, the switch 100 being connected by a wire 102 with a wire 107. The other side of the switch is connected by a wire 103 with a bridge plate 104C and this plate is connected 'by a wire 105 with the wire 89 and thence with the stop plate 76. When, therefore,

the push button is operated a connection is 'made through the control motor and it is started in action so that the brush is carried over on to the stop plate 73 and either stops there or advances depending on the condition of the thermal element 77.

lt will be seen, that there are two normal control circuits leading from the hot and cold side 79 and 78 and that there is a control motor circuit leading through the wire 79 and its branches which is controlled through the control switch, and that there is an emergency circuit through the Happer switch 92. lt will also be observed that in the movable element of the switch there are two plates, or switch elements, which are covered simultaneously by the brush or other element of the switch. This overlapping makes it possible to form a device which will move past the safety stop conditions when the burner is in normal condition, in other words, there is no necessity for outside mechanism to accomplish thispurpose. Further the brush bridges the contact plate so that the control motor is kept running when started so as to move the brush to a new position.

What I claim as new is 1. In a rotating control apparatus, the combination of a control motor; a first normal control connection; a second normal control connection: lan emergency control connection: a control motor connection; and a switch actuated by the motor and normally alternating closures through the control motor connection with the normal control conlll lll

nection's and creating with. an electric curburner motor; a first normal control connection; a second normal control connection; an emergency control connection responsive to-changes in combustion in the burner; a control motor connection; a switch actuated by the control motor and normally alternately closing the cont-rol motor connection with the normal control connections and creating with an electric current change in the emergency control connection a response in the control motor connection stopping the motor with the switch in position unresponsive to the conditions in the normal control connections, said switch maintaining one control motor connection until another is established and means controlled by the control motor controlling the burner motor.

3. ln a rotating control apparatus, the combination ot a control motor; a irst'normal control connection; a second normal control connection; an emergency control connection; a control motor connection; a switch actuated by the motor and normally alternating closures through the control motor connection with the normal control connections and creating with an electric current change in the emergency control connection a response in the control motor connection stopping the motor with the switch in position irresponsive to conditions in the normal connections, said switch maintaining one control motor connection until another control motor connection is established; a.' burner motor; and a switch controlled by the motor controlling the burner motor.

l. ln a rotating control apparatus, the combination of a control motor; a first normal control connection; a second normal control connection; an emergency control connection; a control motor connection; a switch uactuated by the motor and normally alternating closures through the control motor connection with the normal control connections and creating with an electric current change in the emergency control connection a response in the control motor connection stopping the motor with the switch in position irresponsive to conditions in the normal control connections, said switch maintaining one control motorconnection until another control -motor connection is established; a burner motor; and a switch controlled by the motor controlling the burner motor,

`5. In a rotating control apparatus, the combination of a control motor; awarm side thermally controlled normal control connection; a cold side thermally controlled normal control connection; an emergency control connection; a control motor `connection; and a switch actuated by the motor and normally alternately closing the control motor connection with the normal control connections and creating with an electric current change in the emergency control connection a response in the control motor connection stopping the motor with the switch in position irresponsive to the conditions in the normal connections, said switch maintaining one control motor connection until another vis established.

6. ln a rotating control apparatus, the combination of a control motor; a first normal control connection; a second normal control connection; an emergency control connection; a control motor connection; a switch actuated by the motor and normally alternating, closures through the cont-rol motor connection with the normal control connections `and creating with an -electric current change in the emergency control connection a 'response in the control motor connection stopping the motor with the switch in position irresponsive to conditions in the normal control connections, said switch maintaining one control motor connection until another control -motor connection is established; a starting connection; and a manually actuated switch controlling the starting connection, the closing of said switch creating a response in the control connection after the control motor is stopped through a change in the emergency connection.

7. ln a rotating control apparatus, the combination of a control motor; a burner; a first normal control connection; a second normal control connection; an emergency control connection responsive to changes in the combustion in the burner; a control motor connection; and a control switch actuated by the motor normally alternately closing the control motor connection with the normal control connections and creating with an electric current change in the emergency control connection a response in the motor, the control connection stopping the motor with the switch in a position unresponsive to conditions in the normal connections, said switch maintaining one control motor connection until another is established.

8. ln a rotating control apparatus, the combination of a control motor; a burner; a first normal control connection; a. second normal control connection; an emergency control connection responsive to Utl ill)

changes in the combustion in the'burner; a control motor connectlon; a control Switch lactuated by the motor normally alternatel with an electric current change` in the emergency-control connection a response in the motor, the control connection stopping the motor with the switch in a position unresponsive to conditions in the normal connections, said switch maintaining one control motor connection until another is established; a. burner motor; and a burner switch controlling the burner nio-tor said switch being acuated by the contro motor and stopping the burner mot'or with the control switch in position unresponsive to conditions inthe norma-l connections.

9. In a control apparatus, the combination of a rotating control motor; a motor connection; a first normal control connection; a second normal control connection; an emergency control connection; and a control switch actuated by the motor and adapted to close said control connections with the motor connection to complete a circuit through the motor, said switch acting to normally alternately closethe motor connection with the normal control connections, said switch opening the motor connection with a current change in the emergency control connection with the switch in position irresponsive to conditions in the normal connections.

10. ln a control apparatus, the combination of a rotating control motor; a motor connection; a first normal control connection; a second normal control connection; an emergency control connection; and a control switch actuated by the motor` and adapted to close said control connections with the motor connection to complete a circuit through the motor, said switch acting to normally alternately close the motor connections with the normal control connections, said switch opening the motor connection with a current change in the emergency control connection with the switch in position irresponsive to conditions in the normal connections, said switch maintaining one control motor connection until another is established.

1l. In a rotating control apparatus, the combination of a control motor; a burner; a irst normal control connection; a second normal control connection; an emergency control connection responsive to variations in condition of combustion in the burner; a motor connection;'a.nd a "control switch actuated b-y the motor and normally alternately closing the motor connection with the normal control connection and opening the motor connection with a change in the emergency control connectionwith the switch in position irresponsive to conditions in the normal connections.

l l2. ln a rotating control apparatus, the

; combinationof a control motor; a burner; a, lirst normal control connection; a second normal control connection; an emergency control connection responsive-to variations in condition of combustion in the burner; a motor connection; and a control switch actuated by the motor and normally alternatzly closing the motor connection with the normal control connection and opening the motor connection with a change in the emergency control connection with the switch in position irresponsive to conditions in the normal connections, said switch maintaining one control motor connection until another is established.

13. In al rotating control apparatus, the combination of a control motor; a burner; a first normal control connection; a second normal control connection; an emergency control connection responsive to variations in condition of combustion in the burner; a motor connection; a controlling switch actuated by the motor and normally alternatelyA closing th motor connection with the normal control connection and opening the motor connection with a change in the emergency control connection with the switch in position irresponsivey to conditions in the normal connections; a burner motor; and a burner switch actuated by the control motor and positioned to stop the burner as the control switch acts in response to th change in the emergency connection.

14. In a rotating control apparatus; the combination of a control motor; a burner; a first normal control connection; a second normal control connection; an emergency control connection responsive, to variations in condition of combustion in 'the burner: a motor connection; a control switch actuated by the motor and normally alternately closing the motor connection with the normal control connection and opening the Inotor connection with a change in th'c emergency1 control connection withthe switch in position rresponsive to conditions in the normal connections, said switch maintaining one control motor connectionl until another is established; a burner motor; and a burner switch actuated by'th'! control motor and positioned to stop the burner as the control switch acts in response to the change in the emergency connection.

l5. ln a control apparatus, the combina tion of a rotating control motor; a burner: an emergency switch responsive to changes in the combustion in the burner; a single emergency connection controlled said switch: a first normal control connection; a second normal control connection; a control motor connection; and a control switch actuated by the control motor and normallyY alternately closing the control motor connection with the normal control connections and closing the emergency conneo lIO tion'as the emergency switch is actuated to advance the lcontrol switch to a position irresponsive to conditions of the normal connections and in position to stop the control motor. f

16. In a control apparatus, the combination of a rotating control motor; a burner; an emergency switch responsive to changes in the combustion in the burner; a single emergency connection controlled by said switch; a rst normal control connection;

a second normal control connection; a control m'otor connection; a control switch actuated by the control motor and normally alternately closing the control motor conc nection with the normal control connections f tion of a rotating' control motor; aburner;

an emergency switch responsive to changes in the combustion in the burner; a single emergency connection controlled by said switch; a first normal control connection; a second normal control connection; a control motor connection; a control switch actuated by the control motor and normally alternately closing .the control motor connection with rthe normal control connections and closing the emergency connection as the emergency switch is actuated to advance the control switch to a position irresponsive to conditions of the normal connections and in position to stop the control motor; a single starting connection; and a normally controlled switch-controlling the starting connection, said starting connection acting with the controlling switch to close the control i motor connection after the motorhas been iso stopped in response to the action of the emergency control connection.

18. In a control apparatus, the combination of a rotating control motor; a rotaryswitchactuated by the motor having'a brush member and a plate member having 'relative rotary movement, the plate member havingv a series of contact plates; a control motor connect-ion; and connections extending from the plates and forming with the control motor. connection a control circuit controlling the motor to move the switch When a control connection extending from the plate covered by the brush is closed, one of the plates overlappingl another in brush relation and completing the motor circuit to advance the switch over one of the overlapping plates. without the closure of the connection extending from the last-mentioned plate.

19. In a co-ntrol apparatus, the combination of`a rotating control motor; a rotary switch actuated by the motor having a brush member and a plate member, the plate member having a series of contact plates; a control motor connection throughvthe brush; and control connections extending from the plates and forming with the control motor connection a control circuit controlling the motor to-move the switch when a control connection extending from aplate covered by the brush is closed, one of the plates overlap-ping another plate in brush relation and completing a brush connection to actuate the motor to advance theswitch over one of the overlapping plates without a closure of the connection extending from the last-mentioned plate.`

20. In a control-apparatus, the combinationl of a rotating control motor; a rotary switch actuated by the motor having a brush member anda plate member having relative rotary movement, the plate member having a series of. contact plates; a control motor connection; and connections extending Jfrom the plates and forming with the control motor connection a control circuit lcontrolling the motor to move the switch when a control connection extending from the plate covered bythe brush is closed, one of the plates overlapping another in brush relation A and completing the motor circuit to advance the switch over one of the overlapping plates without a closure of the connection extendingV from the last-mentioned plate, said brush having a relation to the plates closing a connection as rit advances with a succeeding plate before breaking the connection with the plate in circuit.

'21. -In a control apparatus, the combination of a rotating control motor; a rotary switch actuated by the motor having a brush member and a plate member,'the plate member having a series of contact plates; a. control motor connection through the brush; and control connections extending from the plates and forming with the control motor connection a control circuit controlling the motor to move the switch when. a control connection extending from a plate covered by the brush is closed,one of the plates overlapping another plate in brush rela` tion and completing a brush connection to actuate the motor to advance the switch over one of the overlapping plates without a closure of the connection extending from the last-mentioned plate, said brush having a relation to the platesy closing a connection as it advances with a succeeding plate before breaking the connection with the plate in circuit. Q

22. In a control apparatus, the combination of a rotating control motor; a first lon lao

normal control connection; a second normal control connection; an emergency control connection; a control motor connection; and a rotary control switch actuated by the motor and having a brush member and a. plate member, the plate member having a series of contact plates, one connected with the first control connection, a second connected with the second control connection, and a third connected with the emergency control connection, said plates withv their connections closed forming with the control motor connection a motor controlled circuit with the brush on a plate having itsconnection closed and moving the brush from a plate in circuit., one of the plates connected with one of the normal connections overlapping the plate having the emergency connection in brush relation and completing a circuit controlling the advance of the switch over the emergency plate without a closure of the emergency connection.

23. lin a control apparatus, the combination of a rotating control motor; a tirst normal control connection; a second normal control connection; an emergency control connection; a control motor connection; and a rotary control switch actuated by the motor and having a brush member and a plate member, the plate member having a series of contact plates, one connected with the first control connection, a second connected with the second control connection, and a third connected with the emergency control connection, said plates with their connections closed forming'with the control motor connection a motor controlled circuit and moving the brush from a plate in circuit, one of the plates connected with one of the normal connections overlapping the plates having the emergency connection in brush relation and completing a circuit controlling the advance of the switch over the emergency plate without a closure 'of the emergency connection, the brush extending from one plate to another to complete a connection as it advances with a succeeding plate before breaking the connection with the plate in circuit 24. In a control apparatus, the combination of a rotatin control motor; a thermally, actuated co d side normal control connection; a thermally actuated Warm side normal control connection; a burner; an ,emergency control connection responsive to combustion conditions in the burner; a control motor connection; a control switch actuated by the motor, said switch comprising a brush member and a plate member, said members having relative rotary motion, the

plate member having aseries of plates, anl

emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate, and a stop plate connected with the warm side normal connection, the motor connection acting with the above-mentioned connections closed to form a motor control circuit, the running plate having'A an overlapping brush relation in respect to the emergency plate whereby a connection maybe made through the cold side normal connection to advance the switch without a closure of the emergency connection'.

25. lin a control apparatus, the combination of a rotating controlli motor; a thermally actuated cold side normal control connection; a thermally actuated warm side normal control connection; a burner; an emergency control connection responsive to combustion conditions in the burner; a control motor connection; and a control switch actuated by the motor, said switch comprising a brush member and a plate member, said members having relative rotary motion, theplate member having a series of plates, an emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate; and a stop plate connected with the warm yside normal connection, the motor connection acting with the above-mentioned connections when closed to form a motor control circuit, the running plate having an overlapping brush relation in respect to the emergency plate whereby a connection may be made through the cold side normal connection to advance the switch without a closure of the emergency connection, the brush closing the connection as it advances with a succeeding plate before breaking the connection with the plate in circuit.

26. ln a control apparatus, the combination of a rotating controlv motor; a thermally actuated cold side normal control connection; a thermally actuated warm side normal control connection a burner; an emergency control connection responsive to combustion conditions in the burner; a control motor connection; and a control switch actuated by the motor, said switch comprising a brush member and a plate member, said members having relative rotary motion, the plate member having a series of plates, an emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate, and a stop plate connected with the warm side normal connection, the motor connection acting with the above-mentioned connections when closed to form a motor control circuit, the running plate having an overlapping brush relation in respect to the emergency plate whereby a connection may be made through the cold side normal connection to advance the switch without a closure of the-emergency connection; and a when Htl@

llt)

starting connection. leading to thestop plate closing the circuit as the starting connection is'closed.

27. In a control apparatus, the combination of a rotating control motor; a thergency connection, a running plate connected to the cold side normal connection, a-

stop plate connected with the running plate, a vstop plate connected with the warm side normal connection, and a retarding plate in the motor connection,l the motor vconnection acting with the above-mentioned connections when closed to 'form a motor control circuit, the running plate having an overlapping brush relation in respect to the emergency plate whereby a connection may be made through'the cold side normal connection to advance the switch without a closure of the emergency connection.

28. ln a control apparatus, the combination of a rotating control motor; a thermally actuated cold side normal control connection; a thermally actuated warm side normal control connection; a burner; an emergency control connection responsive to comustion conditions in the burner; a control switch actuated by the motor, said switch comprising a brush member and a plate member, said members having relative rotary motion, the plate member having a series of plates, an emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate, and a stopplate connected with the warm side normal connection; and a control motor connection vthrough the brush, said motor connection acting with the abovementioned connections When closed to form a motor control circuit, the running plate having an overlapping brush relation in respect to the emergency plate whereby a connection may 4beY made through the cold side normal connection to advance the switch without a closure of the emergency connection.

29. lfn a control apparatus, the combination of a rotating control motor; a thermally actuated cold side normal control connection; a thermally actuated warm side normal control connection; a burner; an emergency control connection responsive to combustion conditions in the burner; a control switch actuated by the motor, said 'switch comprising abrush member and a plate member, said members having relative ro tary motion, the plate member having a series of plates, an emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate, and a stop plate connected with the Warm side normal connection; and a control motor connection through-the brush, said motor. connection acting with the abovementioned connections when closed to form a control circuit, the running plate having an overlappingbrush relation in respect to the emergency plate whereby a connection may be made through the cold side normal connection to advance the switch without a closure of the emergency connection, and a starting connection leading to the stop plate closing the circuit as the starting connection'is closed.

30. ln a control apparatus, the combination oit a rotating control motor; a thermally actuated cold side normal control connec tion; a thermally actuated Warm side normal control connection; a burner; an emergency control connection responsive to combustion conditions in the burner; a control switch actuated by the motor, said vswitch comprising a brush member and a plate member, said members having relative rotary motion, ther plate member having a series oit plates, an emergency plate connected to the emergency connection, a running plate connected to the cold side normal connection, a stop plate connected with the running plate, a stop plate, connected with the warm side normalwconnection, and a retarding plate in the motor connection; and

a control motor 'connection through the 1 brush, the motor connectioil-.; acting with the above-mentioned connect1ons when closed to term a motor control circuit, the

running plate having an overlappingbrush relation in respect, to the emergency plate whereby a connection may be made through the cold side normal connection to advance the switch without a closure ofthe emergency connection 31, ln a control apparatus, the combination of a control motor; a thermally actuated cold side normal control connection; a thermally actuated warm side normal control connection; a burner; an emergency control connection responsive to combustion conditions in the burner; a control switch actuated by the motor, said switch comprising a brush member and a plate member, said members having relative rotary motion, the plate member having a series of plates, an emergency plate connected to the emer ency connection, a running plate connect'e to the cold side normal connection, a stop plate connected with the running plate, and a stop plate connected with the warm nection to advance the switch Without a. closure of the emergency connection, the

brush closing the connection as it advances with a succeeding plate before breaking the connection with the plate in circuit.

In testimony whereof I have hereunto set my hand.

RBERT F. METCALFE. 

